rough draft

Author: kaitlynmichael

content/operate/kubernetes/re-databases/modules.md

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+---
+Title: Redis modules on Kubernetes
+alwaysopen: false
+categories:
+- docs
+- operate
+- kubernetes
+description: Deploy Redis Enterprise databases with modules using the Redis Enterprise operator for Kubernetes.
+linkTitle: Redis modules
+weight: 15
+---
+
+Redis Enterprise modules extend Redis functionality with additional data types, commands, and capabilities. The Redis Enterprise operator supports deploying databases with modules through the `RedisEnterpriseDatabase` (REDB) and `RedisEnterpriseActiveActiveDatabase` (REAADB) custom resources.
+
+## Prerequisites
+
+Before you begin, verify that you have:
+
+- Redis Enterprise operator deployed in your Kubernetes cluster
+- Redis Enterprise Cluster (REC) running and in a healthy state
+- Modules uploaded to the Redis Enterprise cluster (see [Check available modules](#check-available-modules))
+
+## Available modules
+
+Redis Enterprise includes several built-in modules:
+
+- **RediSearch** (`search`) - Full-text search and secondary indexing
+- **RedisJSON** (`ReJSON`) - JSON data type support
+- **RedisTimeSeries** (`timeseries`) - Time series data structures
+- **RedisBloom** (`bf`) - Probabilistic data structures (Bloom filters, etc.)
+- **RedisGraph** (`graph`) - Graph database capabilities
+- **RedisGears** (`rg`) - Programmable data processing engine
+
+## Check available modules
+
+Before configuring databases with modules, check which modules are available in your cluster:
+
+```bash
+kubectl get rec <cluster-name> -o jsonpath='{.status.modules}' | jq
+```
+
+This command shows the modules installed in the cluster along with their available versions.
+
+## Install additional modules
+
+If you need to install additional modules or specific versions, upload them using the Redis Enterprise API:
+
+1. Get cluster credentials:
+
+   ```bash
+   kubectl get secret <cluster-name> -o jsonpath='{.data.username}' | base64 -d
+   kubectl get secret <cluster-name> -o jsonpath='{.data.password}' | base64 -d
+   ```
+
+2. Port forward to the cluster API:
+
+   ```bash
+   kubectl port-forward service/<cluster-name> 9443:9443
+   ```
+
+3. Upload the module:
+
+   ```bash
+   curl -k -u <username>:<password> -X POST \
+     -F 'module=@<path-to-module-file>' \
+     https://localhost:9443/v2/modules
+   ```
+
+## Configure databases with modules
+
+### Basic database with modules
+
+The following example shows a `RedisEnterpriseDatabase` with modules:
+
+```yaml
+apiVersion: app.redislabs.com/v1alpha1
+kind: RedisEnterpriseDatabase
+metadata:
+  name: search-db
+  labels:
+    app: redis-enterprise
+spec:
+  redisEnterpriseCluster:
+    name: rec
+  memorySize: 1GB
+  shardCount: 1
+  replication: false
+
+  # Configure modules
+  modulesList:
+    - name: search
+      config: "MAXSEARCHRESULTS 10000 MAXAGGREGATERESULTS 10000"
+    - name: ReJSON
+```
+
+### Database with multiple modules
+
+The following example shows a database configured with multiple modules:
+
+```yaml
+apiVersion: app.redislabs.com/v1alpha1
+kind: RedisEnterpriseDatabase
+metadata:
+  name: multi-module-db
+  labels:
+    app: redis-enterprise
+spec:
+  redisEnterpriseCluster:
+    name: rec
+  memorySize: 2GB
+  shardCount: 2
+  replication: true
+
+  modulesList:
+    - name: search
+      config: "MAXSEARCHRESULTS 50000"
+    - name: ReJSON
+    - name: timeseries
+      config: "RETENTION_POLICY 86400000"
+    - name: bf
+```
+
+### Active-Active database with modules
+
+For Active-Active databases, you must specify modules with explicit versions:
+
+```yaml
+apiVersion: app.redislabs.com/v1alpha1
+kind: RedisEnterpriseActiveActiveDatabase
+metadata:
+  name: aa-search-db
+  labels:
+    app: redis-enterprise
+spec:
+  participatingClusters:
+    - name: cluster-east
+    - name: cluster-west
+
+  redisEnterpriseDatabase:
+    memorySize: 1GB
+    shardCount: 1
+    replication: true
+
+    modulesList:
+      - name: search
+        version: "2.8.4"
+        config: "MAXSEARCHRESULTS 10000"
+      - name: ReJSON
+        version: "2.6.6"
+```
+
+## Module configuration
+
+### Module parameters
+
+Each module in the `modulesList` supports the following fields:
+
+- **name** (required): The module name (for example, "search", "ReJSON")
+- **version** (optional for REDB, required for REAADB): Specific module version
+- **config** (optional): Module-specific configuration parameters
+
+### Common module configurations
+
+#### RediSearch
+
+```yaml
+- name: search
+  config: "MAXSEARCHRESULTS 10000 MAXAGGREGATERESULTS 5000 TIMEOUT 500"
+```
+
+#### RedisTimeSeries
+
+```yaml
+- name: timeseries
+  config: "RETENTION_POLICY 86400000 MAX_SAMPLE_PER_CHUNK 360"
+```
+
+#### RedisBloom
+
+```yaml
+- name: bf
+  config: "ERROR_RATE 0.01 INITIAL_SIZE 1000"
+```
+
+## Best practices
+
+### Module version management
+
+- For production environments, specify explicit module versions in Active-Active databases
+- Use the cluster's available modules list to ensure compatibility
+- Test module upgrades in non-production environments first
+
+### Resource planning
+
+- Modules consume additional memory and CPU resources
+- Plan cluster resources accordingly when using multiple modules
+- Monitor module-specific metrics and performance
+
+### Configuration management
+
+- Use module configuration parameters to optimize performance
+- Document module configurations for consistency across environments
+- Consider module-specific backup and recovery requirements
+
+### Upgrade considerations
+
+- Ensure compatible module versions before cluster upgrades
+- Upload required module versions before upgrading the cluster
+- Review module compatibility matrices in Redis Enterprise documentation
+
+## Troubleshooting
+
+### Common issues
+
+1. **Module not available error:**
+   - Check if the module is installed: `kubectl get rec <cluster-name> -o jsonpath='{.status.modules}'`
+   - Upload the module if missing using the API endpoint
+
+2. **Version compatibility issues:**
+   - Verify module version compatibility with your Redis Enterprise version
+   - Check the Redis Enterprise documentation for supported module versions
+
+3. **Configuration errors:**
+   - Validate module configuration parameters
+   - Check Redis Enterprise logs for specific error messages
+
+### Debugging commands
+
+```bash
+# Check cluster status and available modules
+kubectl get rec <cluster-name> -o yaml
+
+# Check database status
+kubectl get redb <database-name> -o yaml
+
+# View operator logs
+kubectl logs -l name=redis-enterprise-operator
+
+# Check cluster logs
+kubectl logs <cluster-pod-name>
+```
+
+## Examples
+
+See the `deploy/examples/` directory for additional configuration examples:
+
+- Basic database: `deploy/examples/v1alpha1/redb.yaml`
+- Active-Active database: `deploy/examples/v1alpha1/reaadb.yaml`
+
+## Related information
+
+- [Database controller]({{< relref "/operate/kubernetes/re-databases/db-controller" >}}) - Learn how to create and manage Redis Enterprise databases
+- [Active-Active databases]({{< relref "/operate/kubernetes/active-active" >}}) - Set up globally distributed Active-Active databases
+- [Database connectivity]({{< relref "/operate/kubernetes/networking/database-connectivity" >}}) - Connect applications to your Redis Enterprise databases
+- [REDB API reference]({{< relref "/operate/kubernetes/reference/api/redis_enterprise_database_api" >}}) - Complete API specification for REDB resources
+- [REAADB API reference]({{< relref "/operate/kubernetes/reference/api/redis_enterprise_active_active_database_api" >}}) - API reference for Active-Active databases
+- [Redis modules documentation](https://redis.io/docs/latest/develop/reference/modules/) - Official Redis modules documentation